In his five years as president, Mr. Mandela, though still a sainted figure abroad, lost some luster at home as he strained to hold together a divided populace and to turn a fractious liberation movement into a credible government.

Some blacks — including Winnie Madikizela-Mandela, Mr. Mandela’s former wife, who cultivated a following among the most disaffected blacks — complained that he had moved too slowly to narrow the vast gulf between the impoverished black majority and the more prosperous white minority. Some whites said he had failed to control crime, corruption and cronyism. Some blacks deserted government to make money; some whites emigrated, taking capital and knowledge with them.

Undoubtedly Mr. Mandela had become less attentive to the details of governing, turning over the daily responsibilities to the deputy who would succeed him in 1999, Thabo Mbeki.

After leaving the presidency, Mr. Mandela brought that moral stature to bear elsewhere around the continent, as a peace broker and champion of greater outside investment.

Mr. Mandela was deep into a life prison term when he caught the notice of the world as a symbol of the opposition to apartheid, literally “apartness” in the Afrikaans language — a system of racial gerrymandering that stripped blacks of their citizenship and relegated them to reservation-style “homelands” and townships.

Around 1980, exiled leaders of the foremost anti-apartheid movement, the African National Congress, decided that this eloquent lawyer was the perfect hero to humanize their campaign against the system that denied 80 percent of South Africans any voice in their own affairs. “Free Nelson Mandela,” which was already a liberation chant within South Africa, became a pop-chart anthem in Britain, and Mr. Mandela’s face bloomed on placards at student rallies in America aimed at mustering trade sanctions against the apartheid regime.

Mr. Mandela noted with some amusement in his 1994 autobiography, “Long Walk to Freedom,” that this congregation made him the world’s best-known political prisoner without knowing precisely who he was. Probably it was just his impish humor, but he claimed to have been told that when posters went up in London, many young supporters thought Free was his Christian name.

In South Africa, though, and among those who followed the country’s affairs more closely, Nelson Mandela was already a name to reckon with.

He was born Rolihlahla Mandela on July 18, 1918, in Mvezo, a tiny village of cows, corn and mud huts in the rolling hills of the Transkei, a former British protectorate in the south. His given name, he enjoyed pointing out, translates colloquially as “troublemaker.” He received his more familiar English name from a teacher when he began school at age 7. His father, Gadla Henry Mphakanyiswa, was a chief of the Thembu people, a subdivision of the Xhosa nation.

When Nelson was an infant, his father was stripped of his chieftainship by a British magistrate for insubordination — showing a proud stubborn streak his son willingly claimed as an inheritance.

Nine years later, on the death of his father, young Nelson was taken into the home of the paramount chief of the Thembu — not as an heir to power, but in a position to study it. He would become worldly and westernized, but some of his closest friends would always attribute his regal self-confidence (and his occasional autocratic behavior) to his upbringing in a royal household.

Unlike many black South Africans, whose confidence had been crushed by generations of officially proclaimed white superiority, Mr. Mandela never seemed to doubt that he was the equal of any man. “The first thing to remember about Mandela is that he came from a royal family,” said Ahmed Kathrada, an activist who shared a prison cellblock with Mr. Mandela and was part of his inner circle. “That always gave him a strength.”

In his autobiography, Mr. Mandela recalled eavesdropping on the endless consensus-seeking deliberations of the tribal council, and noticing that the chief worked “like a shepherd.”

“He stays behind the flock,” he continued, “letting the most nimble go out ahead, whereupon the others follow, not realizing that all along they are being directed from behind.”

That would often be his own style as leader and president.

Mr. Mandela maintained his close ties to the royal family of the Thembu tribe, a large and influential constituency in the important Transkei region. And his background there gave him useful insights into the sometimes tribal politics of South Africa.

Mr. Mandela once explained in an interview that the key to peace in the Zulu nation was simple: Mr. Buthelezi had been raised as a member of the royal Zulu family, but as a nephew, not in the direct line of succession, leaving him tortured by a sense of insecurity about his position. The solution was to love him into acquiescence.

The enlarging of Mr. Mandela’s outlook began at Methodist missionary schools and the University College of Fort Hare, then the only residential college for blacks in South Africa. Mr. Mandela said later that he had entered the university still thinking of himself as a Xhosa first and foremost, but left with a broader African perspective.

Studying law at Fort Hare, he fell in with Oliver Tambo, another leader-to-be of the liberation movement. The two were suspended for a student protest in 1940 and sent home on the verge of expulsion. Much later, Mr. Mandela called the episode — his refusal to yield on a minor point of principle — “foolhardy.”

On returning to his home village, he learned that his family had chosen a bride for him. Finding the woman unappealing and the prospect of a career in tribal government even more so, he ran away to the black metropolis of Soweto, following other young blacks who had left mostly to work in the gold mines around Johannesburg.

There he was directed to Walter Sisulu, who ran a real estate business and was a spark plug in the African National Congress. Mr. Sisulu looked upon the tall young man with his aristocratic bearing and confident gaze and, he recalled in an interview, decided that his prayers had been answered.

Mr. Mandela soon impressed the activists with his ability to win over doubters. “His starting point is that ‘I am going to persuade this person no matter what,’ ” Mr. Sisulu said. “That is his gift. He will go to anybody, anywhere, with that confidence. Even when he does not have a strong case, he convinces himself that he has.”

Mr. Mandela, though he never completed his law degree, opened the first black law partnership in South Africa with Mr. Tambo. He took up amateur boxing, rising before dawn to run roadwork. Tall and slim, he was also somewhat vain. He wore impeccable suits, displaying an attention to fashion that would much later be evident in the elegantly bright loose shirts of African cloth that became his trademark.

Impatient with the seeming impotence of their elders in the African National Congress, Mr. Mandela, Mr. Tambo, Mr. Sisulu and other militants organized the A.N.C. Youth League, issuing a manifesto so charged with Pan-African nationalism that some of their nonblack sympathizers were offended.

Africanism versus nonracialism: that was the great divide in liberation thinking. The black consciousness movement, whose most famous martyr was Steve Biko, argued that before Africans could take their place in a multiracial state their confidence and sense of responsibility must be rebuilt.

Mr. Mandela, too, was attracted to this doctrine of self-sufficiency.

“I was angry at the white man, not at racism,” he wrote in his autobiography. “While I was not prepared to hurl the white man into the sea, I would have been perfectly happy if he climbed aboard his steamships and left the continent of his own volition.”

In his conviction that blacks should liberate themselves, he joined friends in breaking up Communist Party meetings because he regarded Communism as an alien, non-African ideology, and for a time he insisted that the A.N.C. keep a distance from Indian and mixed-race political movements.

He was also, already, a man of audacious self-confidence.

Joe Matthews, who worked for Mr. Mandela in the Youth League (and later became a moderate voice in the rival Inkatha movement), heard Mr. Mandela speak at a black-tie dinner in 1952 and predict, in what the audience took as impudence, that he would be the first president of free South Africa.

“He was not a theoretician, but he was a doer,” Mr. Matthews said in an interview for the television documentary program “Frontline.” “He was a man who did things, and he was always ready to volunteer to be the first to do any dangerous or difficult thing.”

Five years after forming the Youth League, the young rebels engineered a generational takeover of the African National Congress.

During his years as a young lawyer in Soweto, Mr. Mandela married a nurse, Evelyn Ntoko Mase, and they had four children, including a daughter who died at 9 months. But the demands of his politics kept him from his family. Compounding the strain was his wife’s joining the Jehovah’s Witnesses, a sect that abjures any participation in politics. The marriage grew cold and ended with abruptness.

“He said, ‘Evelyn, I feel that I have no love for you anymore,’ ” his first wife said in an interview for a documentary film. “ ‘I’ll give you the children and the house.’ ”

Not long afterward, a friend introduced him to Nomzamo Winifred Madikizela, a stunning and strong-willed medical social worker 16 years his junior. Mr. Mandela was smitten, declaring on their first date that he would marry her. He did so in 1958, while he and other activists were in the midst of a marathon trial on treason charges. His second marriage would be tumultuous, producing two daughters and a national drama of forced separation, devotion, remorse and acrimony.

In 1961, with the patience of the liberation movement stretched to the snapping point by the police killing of 69 peaceful demonstrators in Sharpeville township the previous year, Mr. Mandela led the African National Congress onto a new road of armed insurrection.

It was an abrupt shift for a man who, not many weeks earlier, had proclaimed nonviolence an inviolable principle of the A.N.C. He later explained that forswearing violence “was not a moral principle but a strategy; there is no moral goodness in using an ineffective weapon.”

Taking as his text Che Guevara’s “Guerrilla Warfare,” Mr. Mandela became the first commander of a motley liberation army, grandly named Umkhonto we Sizwe, or Spear of the Nation.

Although he denied it throughout his life, there is persuasive evidence that about this time Mr. Mandela briefly joined the South African Communist Party, the A.N.C.’s partner in opening the armed resistance. Mr. Mandela presumably joined for the party’s connections to Communist countries that would finance the campaign of violence. Stephen Ellis, a British historian who in 2011 found reference to Mr. Mandela’s membership in secret party minutes, said Mr. Mandela “wasn’t a real convert; it was just an opportunist thing.”

Mr. Mandela’s exploits in the “armed struggle” have been somewhat mythologized. During his months as a cloak-and-dagger outlaw, the press christened him “the Black Pimpernel.” But while he trained for guerrilla fighting and sought weapons for Spear of the Nation, he saw no combat. The A.N.C.’s armed activities were mostly confined to planting land mines, blowing up electrical stations and committing occasional acts of terrorism against civilians.

After the first free elections in South Africa, Spear of the Nation’s reputation was stained by admissions of human rights abuses in its training camps, though no evidence emerged that Mr. Mandela was complicit in them.

That trial resulted in a three-year sentence, but it was just a warm-up for the main event. Next Mr. Mandela and eight other A.N.C. leaders were charged with sabotage and conspiracy to overthrow the state — capital crimes. It was called the Rivonia trial, for the name of the farm where the defendants had conspired and where a trove of incriminating documents was found — many in Mr. Mandela’s handwriting — outlining and justifying a violent campaign to bring down the regime.

At Mr. Mandela’s suggestion, the defendants, certain of conviction, set out to turn the trial into a moral drama that would vindicate them in the court of world opinion. They admitted that they had organized a liberation army and had engaged in sabotage and tried to lay out a political justification for these acts. Among themselves, they agreed that even if sentenced to hang, they would refuse on principle to appeal.

The four-hour speech with which Mr. Mandela opened the defense case was one of the most eloquent of his life, and — in the view of his authorized biographer, Anthony Sampson — it established him as the leader not only of the A.N.C. but also of the international movement against apartheid.

Mr. Mandela described his personal evolution from the temptations of black nationalism to the politics of multiracialism. He acknowledged that he was the commander of Spear of the Nation, but asserted that he had turned to violence only after nonviolent resistance had been foreclosed. He conceded that he had made alliances with Communists — a powerful current in the prosecution case in those cold war days — but likened this to Churchill’s cooperation with Stalin against Hitler.

He finished with a coda of his convictions that would endure as an oratorical highlight of South African history.

“I have fought against white domination, and I have fought against black domination,” he told the court. “I have cherished the ideal of a democratic and free society in which all persons will live together in harmony and with equal opportunities. It is an ideal for which I hope to live for and to see realized. But my lord, if it needs be, it is an ideal for which I am prepared to die.”

Under considerable pressure from liberals at home and abroad (including a nearly unanimous vote of the United Nations General Assembly) to spare the defendants, the judge acquitted one and sentenced Mr. Mandela and the others to life in prison.

Mr. Mandela was 44 when he was manacled and put on a ferry to the Robben Island prison. He would be 71 when he was released.

Robben Island, in shark-infested waters about seven miles off Cape Town, had over the centuries been a naval garrison, a mental hospital and a leper colony, but it was most famously a prison. For Mr. Mandela and his co-defendants, it began with a nauseating ferry ride, during which guards amused themselves by urinating down the air vents on the prisoners below.

The routine on Robben Island was one of isolation, boredom and petty humiliations, met with frequent shows of resistance. By day the men were marched to a limestone quarry, where the fine dust stirred up by their labors glued their tear ducts shut.

But in some ways prison was less arduous than life outside in those unsettled times. For Mr. Mandela and others, Robben Island was a university. In whispered conversations as they hacked at the limestone, and in tightly written polemics handed from cellblock to cellblock, the prisoners debated everything from Marxism to circumcision.

Mr. Mandela learned Afrikaans, the language of the dominant whites, and urged other prisoners to do the same.

Almost from his arrival he assumed a kind of command. The first time his lawyer, George Bizos, visited him, Mr. Mandela greeted him and then introduced his eight guards by name — to their amazement — as “my guard of honor.” The prison authorities began treating him as a prison elder statesman.

During his time on the island, a new generation of political inmates arose, defiant veterans of a national student uprising who at first resisted the authority of the elders but gradually came under their tutelage. Years later Mr. Mandela recalled the young hotheads with a measure of exasperation:

“When you say, ‘What are you going to do?’ they say, ‘We will attack and destroy them!’ I say: ‘All right, have you analyzed how strong they are, the enemy? Have you compared their strength to your strength?’ They say, ‘No, we will just attack!’ ”

Perhaps because Mr. Mandela was so revered, he was singled out for gratuitous cruelties by the authorities. On Robben Island the wardens left newspaper clippings in his cell telling how his wife had been cited as the other woman in a divorce case, and about the persecution she and her children endured after being exiled to a bleak town 250 miles from Johannesburg.

He was denied permission to attend the funerals of his mother and of his oldest son, who died in a car accident while Mr. Mandela was on Robben Island.

Friends say his experiences steeled his self-control and made him, more than ever, a man who buried his emotions deep, who spoke in the collective “we” of liberation rhetoric.

Still, Mr. Mandela said he regarded his prison experience as a major factor in his nonracial outlook. He said prison tempered any desire for vengeance by exposing him to sympathetic white guards who smuggled in newspapers and extra rations, and to moderates within the National Party government who approached him in hopes of opening a dialogue. Above all, prison taught him to be a master negotiator.

Mr. Mandela’s decision to begin negotiations with the white government was one of the most momentous of his life, and he made it like an autocrat, without consulting his comrades, knowing full well that they would resist.

“My comrades did not have the advantages that I had of brushing shoulders with the V.I.P.’s who came here, the judges, the minister of justice, the commissioner of prisons, and I had come to overcome my own prejudice towards them,” he recalled. “So I decided to present my colleagues with a fait accompli.”

With an overture to Kobie Coetsee, the justice minister, and a visit to President P. W. Botha, Mr. Mandela, in 1986, began what would be years of negotiations on the future of South Africa. The encounters, remarkably, were characterized by little rancor and mutual shows of respect. When he occupied the president’s office, Mr. Mandela would delightedly show visitors where President Botha had poured him tea.

Mr. Mandela demanded as a show of good will that Walter Sisulu and other defendants in the Rivonia trial be released. President F. W. de Klerk, Mr. Botha’s successor, complied.

In the last months of his imprisonment, as the negotiations gathered force, he was relocated to Victor Verster Prison outside Cape Town, where the government could meet with him conveniently and monitor his health. (In prison he had had prostate surgery and lung problems, and the government was terrified of the uproar if he died in captivity.) He lived in a warden’s bungalow. He had access to a swimming pool, a garden, a chef and a VCR. A suit was tailored for his meetings with government luminaries.

From the moment they learned of the talks, Mr. Mandela’s allies in the A.N.C. were suspicious, and their worries were not allayed when the government allowed them to confer with Mr. Mandela at his quarters in the warden’s house.

Tokyo Sexwale, who had come to Robben Island as a student rebel, recalled in a “Frontline” interview encountering Mr. Mandela in this comfortable house. Mr. Mandela walked them through the house, showing off the television and the microwave. “And,” Mr. Sexwale said, “I thought, ‘I think you are sold out.’ ”

Mr. Mandela seated his visitors at a table and patiently explained his view that the enemy was morally and politically defeated, with nothing left but the army, the country ungovernable. His strategy, he said, was to give the white rulers every chance to retreat in an orderly way. He was preparing to meet Mr. de Klerk, who had just taken over from Mr. Botha.

In February 1990, Mr. Mandela walked out of prison alongside his wife into a world that he knew little, and that knew him less. The African National Congress was now torn by factions — the prison veterans, those who had spent the years of struggle working legally in labor unions, and the exiles who had spent them in foreign capitals. The white government was also split, with some committed to negotiating an honest new order while others fomented factional violence in hopes of disabling the black political leadership.

Over the next four years Mr. Mandela would be embroiled in a laborious negotiation, not only with the white government, but also with his own fractious alliance.

But first he took time for a victory lap around the world, including an eight-city tour of the United States that began with a motorcade through delirious crowds in New York City.

The anti-apartheid movement had had a rocky relationship with United States governments, which saw South Africa through the lens of the cold war rivalry with Communists and also regarded the country as an important source of uranium. Until the late 1980s the Central Intelligence Agency portrayed the A.N.C. as Communist-dominated. There have been allegations, neither substantiated nor dispelled, that a C.I.A. agent had tipped the police officers who arrested Mr. Mandela.

Congress, following popular sentiment, enacted economic sanctions against investment in South Africa in 1986, overriding the veto of President Ronald Reagan. Even at the time of his euphoric public welcome in the United States, Mr. Mandela was regarded with some official misgivings, because of both his devotion to economic sanctions and his loyalties to various self-styled liberation figures like Col. Muammar el-Qaddafi and Yasir Arafat.

While Mr. Mandela had languished in prison, a campaign of civil disobedience was under way. No one participated more enthusiastically than Winnie Mandela.

By the time of her husband’s imprisonment, the Mandelas had produced two daughters but had little time to enjoy a domestic life. For most of their marriage they saw each other through the thick glass partition of the prison visiting room: for 21 years of his captivity, they never touched.

She was, however, a megaphone to the outside world, a source of information on friends and comrades and an interpreter of his views through the journalists who came to visit her. She was tormented by the police, jailed and banished with her children to a remote Afrikaner town, Brandfort, where she challenged her captors at every turn.

By the time she was released into the tumult of Soweto in 1984, she had became a firebrand. She now dressed in military khakis and boots and spoke in a violent rhetoric, notoriously endorsing the practice of “necklacing” foes, incinerating them in a straitjacket of gasoline-soaked tires. She surrounded herself with young thugs who terrorized, kidnapped and killed blacks she deemed hostile to the cause.

As president, he bowed to her popularity by appointing her deputy minister of arts, a position in which she became entangled in financial scandals and increasingly challenged the government for appeasing whites. In 1995 Mr. Mandela finally filed for divorce, which was granted the next year after an emotionally wrenching public hearing.

Mr. Mandela later fell publicly in love with Graça Machel, the widow of the former president of Mozambique and an activist in her own right for humanitarian causes. They married on Mr. Mandela’s 80th birthday. She survives him, as do his two daughters by Winnie Mandela, Zenani and Zindziswa; a daughter, Makaziwe, by his first wife; 17 grandchildren; and 14 great-grandchildren.

Two years after Mr. Mandela’s release from prison, black and white leaders met in a convention center on the outskirts of Johannesburg for negotiations that would lead, fitfully, to an end of white rule. While outside in the country extremists black and white used violence to tilt the outcome their way, Mr. Mandela and the white president, Mr. de Klerk, argued and maneuvered toward a peaceful transfer of power.

Mr. Mandela understood the mutual need in his relationship with Mr. de Klerk, a proud, dour, chain-smoking pragmatist, but he never much liked or fully trusted him. Two years into the negotiations, the men were jointly awarded the Nobel Peace Prize, and their appearance together in Oslo in 1993 was marked by bouts of pique and recriminations. In a conversation a year after becoming president, with Mr. de Klerk as deputy president, Mr. Mandela said he still suspected Mr. de Klerk of complicity in the murders of countless blacks by police and army units, a rogue “third force” opposed to black rule.

Eventually, though, Mr. Mandela and his negotiating team, led by the former labor leader Cyril Ramaphosa, found their way to the grand bargain that assured free elections in exchange for promising opposition parties a share of power and a guarantee that whites would not be subjected to reprisals.

At times, the ensuing election campaign seemed in danger of collapsing into chaos. Strife between rival Zulu factions cost hundreds of lives, and white extremists set off bombs at campaign rallies and assassinated the second most popular black figure, Chris Hani.

But the fear was more than offset by the excitement in black townships. Mr. Mandela, wearing a hearing aid and orthopedic socks, soldiered on through 12-hour campaign days, igniting euphoric crowds packed into dusty soccer stadiums and perched on building tops to sing liberation songs and cheer.

During elections in April 1994, voters lined up in some places for miles. The African National Congress won 62 percent of the vote, earning 252 of the 400 seats in Parliament’s National Assembly and ensuring that Mr. Mandela, as party leader, would be named president when Parliament convened.

Mr. Mandela was sworn in as president on May 10, and he accepted office with a speech of shared patriotism, summoning South Africans’ communal exhilaration in their land and their common relief at being freed from the world’s disapproval.

“Never, never and never again shall it be that this beautiful land will again experience the oppression of one by another and suffer the indignity of being the skunk of the world,” he declared.

Then nine Mirage fighter jets of the South African Air Force, originally purchased to help keep someone like Mr. Mandela from taking power, roared overhead, and 50,000 roared back from the lawn spread below the government buildings in Pretoria, “Viva the South African Air Force, viva!”

As president, Mr. Mandela set a style that was informal and multiracial. He lived much of the time in a modest house in Johannesburg, where he made his own bed. He enjoyed inviting visiting foreign dignitaries to shake hands with the woman who served them tea.

But he was also casual, even careless, in his relationships with rich capitalists, the mining tycoons, retailers and developers whose continued investment he saw as vital to South Africa’s economy. Before the election, he went to 20 industrialists and asked each for at least one million rand ($275,000 at the exchange rate of that time) to build up his party and finance the campaign. In office, he was unabashed about taking their phone calls — and bristled when unions organized a strike against some of his big donors. He enjoyed socializing with the very rich and the show-business celebrities who flocked to pay homage.

Mr. Mandela exhibited a genius for the grand gesture of reconciliation. Some attempts, like a tea he organized of prominent A.N.C. women and the wives of apartheid-era white officials, were awkward.

Others were triumphant. Few in South Africa, whatever their race, were unmoved in June 1995 when the South African rugby team, long a symbol of white arrogance, defeated New Zealand in a World Cup final, a moment dramatized in the 2009 film “Invictus.” Mr. Mandela strode onto the field wearing the team’s green jersey, and 80,000 fans, mostly Afrikaners, erupted in a chant of “Nel-son! Nel-son!”

Mr. Mandela’s instinct for compromise in the interest of unity was evident in the 1995 creation of the Truth and Reconciliation Commission, devised to balance justice and forgiveness in a reckoning of the country’s history. The panel offered individual amnesties for anyone who testified fully on the crimes committed during the apartheid period.

In the end, the process fell short of both truth (both white officials and A.N.C. leaders were evasive) and reconciliation (many blacks found that information only fed their anger). But it was generally counted a success, giving South Africans who had lost loved ones to secret graves a chance to reclaim their grief, while avoiding the spectacle of endless trials.

There was a limit, though, to how much Mr. Mandela — by exhortation, by symbolism, by regal appeals to the better natures of his constituents — could paper over the gulf between white privilege and black privation.

After Mr. Mandela delivered one miracle in the shape of South Africa’s freedom, it was perhaps too much to expect that he could deliver another in the form of broad prosperity. In his term, he made only modest progress in fulfilling the modest goals he had set for housing, education and jobs.

He tried with limited success to transform the police from an instrument of white supremacy to an effective crime-fighting force. Corruption and cronyism (which predated majority rule) blossomed. Foreign investment, despite the universal high esteem for Mr. Mandela, kept its distance.

Racial divisions, kept in check by the euphoria of the peaceful transition and by Mr. Mandela’s moral authority, re-emerged somewhat as the ultimate problem of closing the income gap remained unresolved.

The South African journalist Mark Gevisser, in his 2007 biography of Mr. Mandela’s successor as president, Thabo Mbeki, wrote: “The overriding legacy of the Mandela presidency — of the years 1994 to 1999 — is a country where the rule of law was entrenched in an unassailable Bill of Rights, and where the predictions of racial and ethnic conflict did not come true. These feats, alone, guarantee Mandela his sanctity. But he was a far better liberator and nation-builder than he was a governor.”

In addition, Mr. Mandela bequeathed his country a virtual one-party system with a circle-the-wagons attitude toward allegations of corruption, a distaste for criticism in the news media and a tendency to treat rival parties as verging on treasonous. Neither liberal nor conservative opposition parties managed to organize themselves into a credible alternative to the A.N.C.

Mr. Mandela himself deferred to his party, notably in the choice of a successor. After the party favorite, Mr. Mbeki, had succeeded to the presidency, Mr. Mandela let it be known that he had actually preferred the younger Mr. Ramaphosa, the former mine workers’ union leader who had negotiated the new Constitution. Mr. Mbeki knew and resented that he was not the favorite, and for much of his presidency he snubbed Mr. Mandela.

Mr. Mandela mostly refrained from directly criticizing his successor, but his disappointment was unmistakable when Mr. Mbeki showed his intolerance of criticism and his conspiratorial view of the world. When Mr. Mbeki questioned mainstream medical explanations of the cause of AIDS, stifling open discussion that might have helped cope with a galloping epidemic, Mr. Mandela spoke up on the need for protected sex and cheaper medicines. When his eldest son, Makgatho, died in 2005, Mr. Mandela gathered family members to publicly disclose that the cause was AIDS.

“There is a great deal of centralization now under President Mbeki, where he takes decisions himself,” Mr. Mandela declared. “We never liked that.”

Mr. Mbeki often found it excruciating to govern in Mr. Mandela’s shadow. He felt his predecessor had dealt him a nearly impossible hand — first by encouraging the notion that South Africa’s liberation was the magic of one great black man, and second by emphasizing accommodation with white power and thus doing relatively little to relieve the impoverished black majority.

In interviews published in Mr. Gevisser’s biography, Mr. Mbeki chafed at President Mandela’s ability to rule by charm and stature, with little attention to the mechanics of governing.

“Madiba didn’t pay any attention to what the government was doing,” Mr. Mbeki said, using the clan name for his predecessor. “We had to, because somebody had to.”

As a former president, Mr. Mandela lent his charisma to a variety of causes on the African continent, joining peace talks in several wars and assisting his wife, Graça, in raising money for children’s aid organizations.

In 2010, the World Cup soccer games took place in South Africa, another sporting-world benediction of the peace Mr. Mandela did so much to deliver to his country. But for Mr. Mandela, the proud occasion turned to heartbreak when his 13-year-old granddaughter Zenani was killed in an auto accident while returning from an opening-day concert. Mr. Mandela, who had been instrumental in luring the tournament to its first African setting, canceled his plans to attend the opening day.

By then, his hearing and memory shaky, he had already largely withdrawn from public debate, declining almost all interview requests and confining himself to scripted public statements on issues like the war in Iraq. (He was vehemently against it.)

When he received a reporter for the 2007 interview, his aides were already contending with a custody battle over Mr. Mandela’s legacy — including where he would be buried and how he would be memorialized. Mr. Mandela insisted that his burial be left to his widow, and be done with minimal fanfare. His acolytes had other plans.